Nowadays, removable electronic appliances, such as removable power supply apparatuses or removable hard discs, are widely used in industrial computers, servers, disk raids, communication apparatuses, etc. The power supply apparatus can provide sufficient and continuous power, and the removable hard disc has sufficient and easily managed information storage space. The removable electronic appliances are advantageous for avoiding inconvenience of frequently pulling out the power supply apparatuses or the hard discs because they are hot swappable.
Take a removable power supply apparatus for example. In order to conveniently pull out respective power supply apparatus for checking and repairing the components therein, the power supply apparatus typically has a handle mounted on a housing thereof. Referring to FIG. 1, a conventional removable power supply apparatus comprises a housing 11, a handle 12 fixed on a surface 13 of the housing 11 and a circuit board (not shown) within the housing 11. The handle 12 is securely held and accessible for a user to pull the appliance. However, since the handle 12 is fixed on the housing 11, the handle 12 fails to be stored and thus wastes space.
Referring to FIGS. 2(a) and 2(b), another removable power supply apparatus having a handle assembly is shown. In FIG. 2(a), the removable power supply apparatus comprises a housing 21, a handle assembly 22 having one end coupled to a surface 211 of the housing 21 and a circuit board (not shown) within the housing 21. The handle assembly 22 comprises a plate 221, a handle 222, a rotating shaft 223, a retaining shaft 224 and a resilience sheet 225. The plate 221 and the handle 222 are integrally formed. Each of the rotating shaft 223 and the retaining shaft 224 has one end (not shown) fixed on the surface 211 of the housing 21. The other end of the rotating shaft 223 penetrates through the plate 221. The plate 221 can be pivoted about the rotating shaft 223. The other end of the retaining shaft 224 moves along a track 226 in the plate 221 between a first position 2261 and a second position 2262. In such configuration, when the plate 221 is pivoted about the rotating shaft 223, the handle 222 is switched in either a stored state or a pulled state. One end of the resilience sheet 225 is coupled to the bottom of the handle 222. The other end of the resilience sheet 225 is distant from the handle 222 and comprises a protrusion 227. The housing 21 further comprises an opening 212. When the handle 222 is in the stored state, the protrusion 227 of the resilience sheet 225 will be urged against the inner wall of the periphery of the opening 212. Therefore, the length and area of the handle 222 extending the housing 21 is shortened.
When the removable power supply apparatus is to be pulled out, the resilience sheet 225 should be firstly pressed down by the forefinger so as to release the protrusion 227 of the resilience sheet 225 from the inner wall of the periphery of the opening 212. Then, a slight pulling force is required to pull the handle 222 toward the user. Accordingly, the handle 222 will drive the plate 221 to pivot about the rotating shaft 223, and the retaining shaft 224 moves along the track 226 from the first position 2261 to the second position 2262 such that the handle 222 is in the pulled state. Meanwhile, the handle 222 has a relatively large force-receiving area and a relatively long force-receiving arm, which is advantageous for pulling the removable power supply apparatus with a low force.
However, the handle assembly shown in FIGS. 2(a) and 2(b) has some drawbacks. For example, since the handle 222 should be extended from the housing 21 to provide a space for the forefinger to press down the resilience sheet 225, the handle 2 still occupies some space outside the housing 21 when stored. In addition, a slight pulling force is required to pull the handle 222 toward the user when the handle 222 is in the pulled state.